Interlaminar-interspinous vertebral stabilization system

ABSTRACT

An implantable interlaminar-interspinous stabilization system is provided. The system may comprise a U-shaped implantable device having an inferior section, a superior section, a midsection extending therebetween, and pair of lateral walls for engaging a spinous process of a vertebra, each of the lateral walls including an aperture with a countersink for receiving a bone fastener. The system may also include a bone fastener comprising a threaded bolt and a threaded nut for securing the implantable device to the spinous processes. Insertion tools may be provided for aligning the threaded bolt and nut through the apertures of the implantable device.

This application claims priority to U.S. Provisional Application No.60/868,080, filed on Nov. 30, 2006, the contents of which are herebyincorporated in its entirety.

FIELD

The present disclosure relates to devices and methods for treatingspinal conditions, including interlaminar-interspinous vertebralstabilization devices and methods of using such devices for stabilizingadjacent vertebrae.

BACKGROUND

Diseases of the spine cause significant morbidity. These diseasesinclude abnormalities of the vertebrae, the intervertebral discs, thefacet joints, and connective tissue around the spine. Theseabnormalities can be due to a number of causes, including mechanicalinjury or degenerative disc disease. Such abnormalities can causeinstability to the spine, allowing the vertebral column to becomemisaligned and producing micromotion between adjacent vertebrae.Vertebral misalignment and micromotion may result in wear to thevertebral bony surfaces and ultimately cause severe pain. Further, theseconditions are often chronic and progressive problems.

The treatments for spinal disorders can include long-term medicalmanagement or surgery. Medical management is generally directed atcontrolling the symptoms, such as pain, rather than correcting theunderlying problem. For some patients, this may require chronic use ofpain medications, which may alter patient mental state or cause othernegative side effects.

Recently, a variety of interspinous stabilization devices have becomeavailable. These devices may be implanted between the spinous processesof two or more adjacent vertebrae. By stabilizing the spinous processesin this way, significant stress may be taken off the intervertebraldiscs to prevent disease progression or to improve conditions such asspinal stenosis. In addition, vertebral motion may be controlled withoutseverely altering spinal anatomy.

Currently available interspinous stabilization systems can be securedbetween adjacent spinous processes using a number of differentmechanisms. For example, such devices can include sharp barbs or othersurface projections that engage the bony surface of a spinous process.In addition, flexible ligaments or sutures can be placed around theimplants and adjacent bone. However, it may be desirable to provide amore rigid and secure attachment to the spinous processes. For example,a rigid attachment may be desirable to prevent the interspinous devicefrom migrating or slipping out of position. In addition, a rigidattachment may be desirable to limit movement and promote fusion at aselected vertebral level. Even further, it may be desirable to provide adevice that can also fit interlaminarly between adjacent vertebrae,thereby enhancing the stability of the region.

The present disclosure describes an interlaminar-interspinous vertebralstabilization system that can be easily implanted and can be securelyattached to the spinous processes while being seated interlaminarly.

SUMMARY

The present disclosure describes an interlaminar-interspinous vertebralstabilization system and a method of using this system for treatingspinal instability conditions. The system includes aninterlaminar-interspinous vertebral stabilization device adapted forplacement between the spinous processes of adjacent vertebrae and a bonefastener for securing the device to the spinous processes. Also providedare insertion tools and methods for using such a system.

One aspect of the disclosure includes an implantableinterlaminar-interspinous stabilization system. The system may comprisea U-shaped implantable device having an inferior section, a superiorsection, a midsection extending therebetween, and pair of lateral wallsfor engaging a spinous process of a vertebra, each of the lateral wallsincluding an aperture with a countersink for receiving a bone fastener.The system may also include a bone fastener comprising a threaded screwand nut for securing the implantable device to the spinous process.Further, insertion tools may be provided for properly aligning thethreaded screw and nut during assembly of the bone fastener through theapertures of the implantable device.

A second aspect of the present disclosure includes an implantableinterlaminar-interspinous stabilization system. The system can comprisean implantable device having an inferior section, a superior section,and pair of lateral walls extending from at least one of the inferiorsection and superior section for engaging a spinous process of avertebra. A U-shaped midsection extending between the inferior andsuperior sections enables the device to be positioned interlaminarlybetween two adjacent vertebrae. Each of the lateral walls can include anaperture for receiving a bone fastener. The system can further include abone fastener comprising a threaded bolt and a threaded nut for securingthe implantable device to the spinous process and an insertion tool foraligning the threaded bolt and nut through the apertures of theimplantable device.

A third aspect of the present disclosure includes a method ofstabilization of a spine. The method can include selecting a vertebrallevel to be treated and positioning a U-shaped implant between twospinous processes of the selected vertebral level. The implant maycomprise an inferior section, a superior section, a midsection extendingtherebetween configured to be seated interlaminarly, and a first pair oflateral walls extending from at least one of the inferior section andsuperior section. The lateral walls are positioned on opposite sides ofone of the spinous processes of the selected vertebral level. Further,each of the lateral walls can include an aperture for receiving a bonefastener, and the implant can be secured to at least one of the spinousprocesses by passing a threaded bolt through the aperture of one of thelateral walls and passing a nut through the aperture of the lateral walllocated on the opposite side of the spinous process such that the nutand bolt pass through the spinous process and are joined at a threadedconnection.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory only,and are not restrictive of the disclosure, as claimed.

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate several embodiments of thedisclosure and together with the description, serve to explain theprinciples of the disclosure.

Additional objects and advantages of the disclosure will be set forth inpart in the description which follows or may be learned by practice ofthe disclosure. The objects and advantages of the disclosure will berealized and attained by means of the elements and combinationsparticularly pointed out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a perspective view of an exemplary embodiment of aninterlaminar-interspinous vertebral stabilization system.

FIG. 2A illustrates a side view of an implantable device of the systemshown in FIG. 1.

FIG. 2B illustrates a cut-away back end view of the device of FIG. 2Aalong line A-A.

FIG. 2C illustrates an enlarged view showing details of FIG. 2B.

FIG. 3 illustrates a perspective view of a bone fastener of theinterlaminar-interspinous vertebral stabilization system, shown in FIG.1.

FIG. 4A illustrates a side view of an insertion tool that may be usedwith the interlaminar-interspinous vertebral stabilization system,according to one exemplary embodiment.

FIG. 4B illustrates a top view of the insertion tool of FIG. 4A.

FIG. 5A illustrates a side view of the insertion tool of FIGS. 4A and 4Bwith the bone fastener of FIG. 3.

FIG. 5B illustrates an enlarged view of a portion of the insertion tooland a portion of the bone fastener of FIG. 5A.

FIG. 5C illustrates another enlarged view of another portion of theinsertion tool and another portion of the bone fastener of FIG. 5A.

FIG. 6A illustrates a side view of a tightening instrument that may beused with the interlaminar-interspinous vertebral stabilization systemof FIG. 1.

FIG. 6B illustrates an enlarged view of an end of the tighteninginstrument of FIG. 6A.

FIG. 7 illustrates a perspective view of the insertion tool of FIG. 5Aand the bone fastener of FIG. 5B in use with the tightening instrumentof FIG. 6A.

FIG. 8 illustrates a perspective view of the insertion tool of FIG. 5Aand the bone fastener of FIG. 3.

FIG. 9 is a perspective view of the implantation of the stabilizationsystem using the insertion tool and tightening instrument of the presentdisclosure.

FIG. 10 is a perspective view of a partially-assembled interspinoussystem, according to one exemplary embodiment.

FIG. 11A illustrates a perspective view of a hole puncher tool that maybe used during implantation of the interlaminar-interspinous vertebralstabilization system of the present disclosure.

FIG. 11B illustrates an enlarged view of the hole puncher tool of FIG.11A.

FIG. 12 illustrates a pair of compression pliers that may be used duringimplantation of the interlaminar-interspinous vertebral stabilizationsystem of the present disclosure.

FIG. 13 illustrates the pair of compression pliers of FIG. 12 duringimplantation of the interlaminar-interspinous vertebral stabilizationsystem of the present disclosure.

DESCRIPTION OF THE EMBODIMENTS

FIG. 1 shows an implantable interlaminar-interspinous vertebralstabilization system 10 for stabilizing adjacent vertebrae. The system10 comprises an implantable device 20 configured for placement betweenthe spinous processes of adjacent vertebrae. The device can include oneor more bone anchors for securing the device to spinous processes.Further, in one embodiment, the bone anchors can rigidly fix the devicewith respect to the spinous processes, thereby limiting movement at aselected vertebral level and promoting fusion at that level.

The device 20 may include a spacer body. The spacer body 20 may havevarious shapes and thicknesses, and can be produced from a variety ofdifferent materials. In one embodiment, the spacer body 20 may include amidsection 30 extending between an inferior section 32 and a superiorsection 34, as shown in FIG. 1. When implanted in a patient, thesuperior section 34 is configured to contact a portion of a firstspinous process, while the inferior section 32 is configured to contacta portion of a second, adjacent spinous process. In one embodiment, themidsection 30, inferior section 32, and superior section 34 may togetherform a substantially U-shaped spacer body 20, as shown. The spacer body20 may be configured to be flexible and/or bendable, such as, forexample, by providing an extendable and/or compressible midsection 30.The midsection 30 can act as a flexible hinge, allowing the superiorsection 34 and inferior section 32 to move away from or towards oneanother. Furthermore, the U-shaped spacer body enables the device 10 tobe positioned, or fitted, interlaminarly after implantation, therebyenhancing the stabilization of the adjacent vertebrae.

To engage the spinous processes of adjacent vertebrae, the spacer body20 may be provided with a pair of lateral walls or brackets 36 thatextend from the inferior and superior sections 32, 34, as shown inFIG. 1. Each of the pair of lateral walls 36 defines a stirrup 38 forreceiving a spinous process. The spacer body 20 can be provided withlateral walls 36 of various sizes or heights to accommodate variationsin patient anatomy. Likewise, the lateral walls 36 of different spacerbodies 20 may be provided at differing locations along the length of theinferior section 32 or superior section 34. The surgeon can thus selecta suitably shaped and sized spacer body 20 depending on the particularvertebral level to be supported and the anatomy of the patient.

Further, the lateral walls 36 may also be adjustable with respect to thespacer body 20. For example, in one embodiment, the lateral walls 36 maybe formed of a malleable material such that, after implantation, thesurgeon may compress the lateral walls 36 together to reduce the gapbetween the lateral walls 36, thereby securely fixing the spacer body 20to a spinous process located therein. In addition, the lateral walls 36may be spread apart to facilitate insertion, as illustrated with theinferiorly located lateral wall 36 of FIG. 1. The lateral walls 36 maybe compressed or spread apart, for example, using surgical pliers orforceps.

A number of biocompatible materials are suitable for forming the spacerbody 20 of the present disclosure. For example, in one embodiment, thespacer body 20 may be formed from a medical grade metal such as titaniumor a titanium alloy. The spacer body 20 may also be formed from avariety of other materials, such as stainless steel, cobalt chrome,ceramics, and/or polymeric materials, such as ultra-highmolecular-weight polyethylene (UHMWPE) and polyetheretherketone (PEEK),either alone or in combination with other suitable materials.

To further enhance the ability of the device 10 to be secured to thesurrounding bone and soft tissue, the device 10 may include a number ofsurface modifications. For example, the spacer body 20 may includesurface alterations that may facilitate tissue attachment, bonding, orfixation. These surface alterations may include teeth, barbs, beads,surface roughening, or the addition of bioactive agents to one or moresections of the device 10. For example, the device 10 may include one ormore barbs 40 for securing the device 10 to bone and/or soft tissue. Asshown, the barbs 40 may be located on the spacer body 20, such as on anouter surface of the inferior section 32 and/or superior section 34.Alternatively, or in addition, the barbs 40 may be located on an innersurface of the lateral walls 36. The barbs 40 may help the spacer body20 securely engage connective tissue or a bony surface of a vertebra,such as the spinous process of the vertebra.

Further, the device 10 may also include roughened or porous surfaces.The roughened or porous surfaces may enhance attachment between implantsurfaces and bone. In addition, some porous surfaces may facilitatetissue ingrowth to form a biological bond between sections of the device10 and the surrounding bone and/or soft tissue. Roughened or poroussurfaces may be included on any portion of the device 10.

The surface of the device 10 may also include biologically activeagents. These agents may include osteogenic factors to furtherfacilitate bonding between components of the device 10 and thesurrounding bone and/or soft tissue. Further, the device 10 may includetherapeutic agents such as antibiotics, steroids, anti-thromboticagents, anti-inflammatory drugs, and/or analgesic agents. In oneembodiment, the biologically active agent may be contained in a coatingon the device. Alternatively, or in addition, the device may be porous,and the biologically active agent may be contained in the pores of thedevice. The biologically active agent may be, for example, bonemorphogenic protein (BMP) for modulating cartilage or bone growth.

The lateral walls or brackets 36 of the present invention can alsoinclude an aperture 50 for receiving a bone fastener to fix the brackets36 to the spinous process. Such fastening members can ensure that thebrackets 36 are pressed flat and/or securely against the spinous processin order to avoid any play of the brackets 36 with respect to theprocess. Further, the system 10 may act as a fusion-promoting devicewhen the implantable device 20 is fastened to the spinous process inthis manner.

The aperture can include a range of sizes and shapes. For example, theaperture 50 may include a countersink 52, as shown in FIG. 2C, to allowfor better seating of a bone fastener 60 against the lateral walls 36.Further, as shown in FIG. 2A, the apertures 50 of the inferior andsuperior sections 32, 34 may be staggered along a longitudinal axis, asthe superior section 34 may be shorter in length than the inferiorsection 32. This feature allows a plurality of the implantable devices20 to be stacked, or implanted, along the spinal column.

Turning now to FIG. 3, the bone fastener 60 can include a bolt 70comprising a head 72 and a threaded, elongate body 74. To secure thebolt 70 within an aperture 50, a nut 80 is provided having a head 82,body portion 84, and threaded inner cavity 86 for receiving thethreaded, elongate body 74 of the bolt 70. As the nut 80 is threadedonto the bolt 70, the lateral walls 36 may be drawn together, as shownin FIG. 1. Thus, the bone fastener 60 and spacer body 20 may form atight, secure connection with the spinous process. In some embodiments,the tight, secure connection between the body 20 and adjacent spinousprocesses will limit movement at the selected vertebral level, therebypromoting fusion at that level. In other embodiments, the nut 80 andbolt 70 may be tightened sufficiently to prevent the spacer body 20 frommoving out of position between the spinous processes, but may be leftsufficiently loose so as to allow a small amount of play between thespacer body 20 and spinous processes, so as not to promote fusion, orcause fusion to occur more slowly. Further, in some embodiments, thesystem 10 can include two bone fasteners 60, so that both the inferiorand superior lateral walls 36 can be securely fastened to spinousprocesses, as shown in FIG. 10 below. Thus, it is contemplated that thedevice 20, when positioned between the spinous processes of two adjacentvertebrae, may be secured to one spinous process and not the otherspinous process, or to both adjacent spinous processes.

FIGS. 4A and 4B illustrate an insertion tool 100 useful for assemblingthe bone fastener 60 during implantation. The insertion tool 100 maycomprise a pair of handles 110 extending into gripping portions 112. Thegripping portions 112 may include a surface modification such as raisedportions 114 to provide a secure gripping surface for the user. Thehandles 110 are connected to one another with a pivotable hinge 120 in amanner similar to pliers and scissors, as is commonly known in the art.Extending distally from each handle 110 is an arm 115 that includes abone fastener holding portion 140A, 140B. The arms 115 are connected tothe handles 110 by a pivotable hinge connection 122. A leaf spring 130may be positioned between the handles 110 to bias the holding portions140A, 140B towards an open position.

As shown in greater detail in FIGS. 5B and 5C, the bone fastener holdingportion 140A can include a cavity configured to securely hold the head72 of the bolt 70 of bone fastener 60 during the implantation process,and the bone fastener holding portion 140B can include a second cavityconfigured to securely hold the head 82 of the nut 80, as shown in FIG.8. Further, this bone fastener holding portion 140B may also include agear mechanism 150, as shown in FIG. 5C. The gear mechanism 150 includesa port 160 extending from the bone fastener holding portion 140B. Theport 160 can include a bore 162 configured to receive a tighteninginstrument 200, shown in FIGS. 6A and 6B. The tightening instrument 200may comprise a shaft 202 extending proximally into a gripping portion204 and distally into a tip 206 that is shaped and configured to fitcomplementarily within the bore 162 of port 160, as shown in FIG. 7.

To assemble the system 10, the implantable device 20 is inserted betweenthe spinous processes of adjacent vertebrae, as shown in FIG. 9. Anyappropriate surgical approach may be used to expose/visualize thespinous processes. After the implantable device 20 has been properlyaligned so that the spinous processes seat securely within the stirrups38 of the device 20, a hole can be punched through the apertures 50 ofeach of the pair of lateral walls 36, the apertures serving as a guidefor placement of the hole through the spinous processes and allowing thebone fastener 60 to be positioned in the hole and through the spinousprocess, as shown in FIGS. 11A and 11B. The holes may be formed using,for example, a hole puncher 300. The hole puncher 300 may comprise apair of arms 312 connected by a leaf spring 320 and a pivotable hinge322. The arms 312 extend proximally into gripping portions 314 anddistally into claws 316. Extending from each claw 316 is a sharp cuttingedge 318 suitable for cutting through bone.

As shown, the sharp cutting edge 318 may be shaped like a cylinder,matching the diameter of the aperture 50 of the implantable device. Thesharp cutting edges 318 may be configured such that they receive andremove the bone as it is cut. For example, as shown, the cylindricalsharp cutting edges 318 can include a hollowed inner region thatreceives bone as it is cut. The cut bone is thereby held by the holepuncher 300 and can be removed after a hole is produced. To ensure thatno extra bone material remains, a surgeon may elect to clean out the cuthole by inserting any suitable tool with a cylindrical tip having thesame diameter as the hole, in one or more repeated steps as needed. Oncethe holes have been made and cleaned, the bone fasteners 60 may then beinserted through the apertures 50 of the lateral walls 36.

To secure the bone fasteners 60 to the seated device 20, the bolt 70 andnut 80 of a bone fastener 60 may be placed into the bone fastenerholding portions 140A, 140B, respectively, of insertion tool 100. Theinsertion tool 100 is then positioned so as to align the bolt 70 and thenut 80 with the apertures 50 of the device 20. When it has beendetermined that the angle and location of the bolt 70 and nut 80 arecorrect, the tightening instrument 200 can be placed into the port 160.Turning the gripping portion 204 causes the rotation of the gearmechanism 150 and rotation of the nut 80, thereby causing the threadingof the nut 80 onto the bolt 70.

The insertion tool facilitates alignment and threading of the bolt 70and nut 80. For example, since there may be limited space available onlateral sides of the walls 36, it may be difficult for a surgeon toposition the bolt 70 and nut 80 through a spinous process. The insertiontool 100 maintains the bolt 70 and nut 80 in the properly alignedposition so as to ensure that they easily thread together duringassembly. Further, the insertion tool 100, and accompanying tighteninginstrument 200, allow easy rotation of the nut 80 to secure thecomponents to one another.

It will be understood that the tightening instrument 200 may beconnected to the insertion tool 100 either before or after the bolt 70and nut 80 are attached to the insertion tool 100, and a bone fastener60 may be threaded through the superior section 34 of the spacer body 20first, then an additional bone fastener 60 may be threaded through theinferior section 32, as shown in FIGS. 9 and 10. Additionally, thetightening instrument 200 enables the user to easily control the desiredtightness by adjusting the number of clockwise and/or counter-clockwiseturns of the gripping portion 204.

In some embodiments, one or more additional instruments may be providedto assist in positioning the spinous processes of the vertebrae to betreated. For example, to properly implant the device 20 between spinousprocesses of the lumbar vertebrae, it may be desirable to position thepatient in a certain degree of lordosis. However, during surgery, thepatient may not be positioned ideally. Therefore, to assist the surgeonin producing the desired degree of lordosis, a pair of compressionpliers 350, as shown in FIG. 12, may be provided.

The compression pliers 350 can include two distal gripping portions 354,358. The gripping portions 354, 358 can be pushed through theinterspinous ligaments located superiorly and inferiorly to the spinousprocesses 366, 370 of a vertebral level to be treated. The grippingportions 354, 358 can then be compressed to push the spinous processes366, 370 towards one another to fit within the stirrups 38 of aninterlaminar-interspinous device 20.

Once properly positioned, the device 20 can be secured to the spinousprocesses 366, 370 using bone anchors 60 and the insertion tool 100described previously. Further, to help maintain the spinous processes366, 370 in the compressed position during insertion of bone anchors 60,the compression pliers 350 can include a locking mechanism 362. Thelocking mechanism can include, for example, a ratchet system positionedat the proximal portion of the compression pliers handles.

In some embodiments, the insertion tool 100, tightening instrument 200,hole puncher 300, and compression pliers 350 can be provided as aninstrument set to be used with one or more devices 20. Accordingly, theinsertion tool 100 and hole puncher can be sized and shaped such that ahole produced with the hole puncher 300 can be properly aligned with abolt 70 and nut 80 provided held by the insertion tool 100.

By firmly securing the implantable device 20 to the spinous processeswith the bone fasteners 60, fusion of bony tissue can be promoted.Further, if desired, additional bone-growth material, such as a bonegraft, may be placed within the midsection 30 of the implantable device20 to enhance bone growth and fusion. It is understood, of course, thatother growth-promoting surface modifications such as, for example, poresor holes may be provided on the surfaces of the implantable device 20 toeffect such ingrowth, as previously described.

In addition, although the device 20 is described with superior andinferior lateral walls 36, the device 20 can include a U-shaped implantwith a single pair of lateral walls 36. Such devices may be used, forexample, at the L5-S1 vertebral level. For example, the device 20 mayinclude a single pair of lateral walls 36 configured to engage thespinous process of the L5 vertebra. Further, the device 20 may include amechanism for securing the inferior section 32 to the sacrum. As notedabove, the superior lateral walls can be secured to the L5 spinousprocess with a bone anchor 60, thereby limiting movement at the L5-S1level and promoting fusion at that level. Various devices and mechanismsfor securing the device 20 to the sacrum are described in co-pendingU.S. patent application Ser. No. 11/400,586, which was filed on Apr. 7,2006, and is herein incorporated by reference in its entirety.

Other embodiments of the invention will be apparent to those skilled inthe art from consideration of the specification and practice of theinvention disclosed herein. It is intended that the specification andexamples be considered as exemplary only, with a true scope and spiritof the invention being indicated by the following claims.

1. An implantable interlaminar-interspinous stabilization systemcomprising: a U-shaped implantable device comprising an inferiorsection, a superior section, a midsection extending therebetween, and apair of lateral walls extending from at least one of the inferiorsection and superior section for engaging a spinous process of avertebra, each of the lateral walls including an aperture for receivinga bone fastener; a bone fastener for securing the implantable device tothe spinous process; an insertion tool for inserting the bone fastenerthrough the apertures of the implantable device during implantation ofthe system; and a tightening tool configured to cooperate with theinsertion tool such that rotation of the tightening tool effectsthreading of the bolt and nut together.
 2. The system of claim 1,wherein the bone fastener comprises a threaded bolt and a threaded nut.3. The system of claim 1, wherein each aperture of the lateral wallsincludes a countersink.
 4. The system of claim 1, wherein the pair oflateral walls extends from the superior section and the system furthercomprises: a second pair of lateral walls extending from the inferiorsection, each of the lateral walls of the second pair of lateral wallsincluding an aperture for receiving a bone fastener.
 5. The system ofclaim 4, further comprising a second bone fastener comprising a threadedbolt and a threaded nut.
 6. The system of claim 4, further including apair of compression pliers for positioning two spinous processes betweenthe first and second pair of lateral walls, respectively.
 7. The systemof claim 1, further including a hole puncher configured to punch a holethrough bony tissue of the spinous process to create a hole configuredto receive the bone fastener.
 8. The system of claim 7, wherein the holepuncher removes bony tissue excised from the spinous process to producethe hole.
 9. The system of claim 1, wherein the midsection iscompressible.
 10. The system of claim 1, wherein the midsection isconfigured to act as a flexible hinge.
 11. The system of claim 1,wherein the pair of lateral walls are movable relative to one another.12. The system of claim 1, wherein the pair of lateral walls are movablerelative to the inferior section or superior section from which thelateral walls extend.
 13. A method of stabilizing a spine, comprising:selecting a vertebral level to be treated; positioning a U-shapedimplant between two adjacent spinous processes of the selected vertebrallevel, the implant comprising: an inferior section, a superior section,a midsection extending therebetween, and a first pair of lateral wallsextending from at least one of the inferior section and superiorsection, each of the lateral walls including an aperture for receiving abone fastener, wherein the pair of lateral walls are positioned onopposite sides of a spinous process of the selected vertebral level; andcreating a hole in the spinous process located between the two lateralwalls of the implant before passing a bolt through the apertures of thelateral walls; and securing the implant to at least one of the adjacentspinous processes by passing the bolt through the aperture of one of thelateral walls.
 14. The method of claim 13, wherein securing the implantincludes aligning a nut with the aperture of the lateral wall located onthe opposite side of the spinous process as the bolt such that thepasses through the spinous process and joins the nut at a threadedconnection.
 15. The method of claim 14, further including tightening thethreaded connection between the nut and bolt to prevent movement of theimplantable device relative to the vertebral level and promote fusion ofthe vertebral level.
 16. The method of claim 14, further including usingan alignment tool to pass the nut and bolt through the apertures of thelateral walls, the alignment tool configured to hold the nut and boltand align threaded portions of the nut and bolt.
 17. The method of claim16, further including tightening the threaded connection between the nutand bolt by turning a gear mechanism of the alignment tool to rotate thenut relative to the bolt and thread the nut to the bolt.
 18. The methodof claim 14, wherein the pair of lateral walls extends from the superiorsection and is positioned on opposite sides of a first spinous process;and the method further includes positioning a second pair of a secondpair of lateral walls on opposite sides of a second spinous process,each of the lateral walls extending from the inferior section andincluding an aperture for receiving a bone fastener and are positioned.19. The method of claim 18, wherein the method includes: securing theimplant to the first spinous process by passing a first bolt through theaperture of one of the lateral walls of the first pair of lateral walls;and securing the implant to the second spinous process by passing asecond bolt through the aperture of one of the lateral walls of thesecond pair of lateral walls.
 20. The method of claim 19, whereinsecuring the implant comprises: aligning a first nut with the apertureof the lateral wall located on the opposite side of the first spinousprocess as the first bolt such that the first bolt passes through thefirst spinous process and joins the first nut at a threaded connection;and aligning a second nut with the aperture of the lateral wall locatedon the opposite side of the second spinous process as the second boltsuch that the second bolt passes through the second spinous process andjoins the second nut at a threaded connection.
 21. The method of claim19, further including tightening the threaded connections between thenuts and bolts to prevent movement of the implantable device relative tothe vertebral level and promote fusion of the vertebral level.
 22. Themethod of claim 21, further including using an alignment tool to passthe nuts and bolts through the apertures of the lateral walls, thealignment tool configured to hold the one of the nuts and one of thebolts and align threaded portions of the nut and bolt.
 23. The method ofclaim 22, further including tightening the threaded connections betweenthe nuts and bolts by turning a gear mechanism of the alignment tool torotate the one of the nuts relative to one of the bolts and thread thenut to the bolt.
 24. The method of claim 19, further including creatinga hole in each of the first spinous process and second spinous processbefore passing the bolts and nuts through the apertures of the lateralwalls.
 25. The method of claim 24, wherein creating the hole includespassing a portion of a punching tool through at least one aperture ofthe lateral walls and through bony tissue of the spinous process. 26.The method of claim 19, further including moving the first spinousprocess and the second spinous process towards one another beforesecuring the implant to the first spinous process and second spinousprocess.
 27. The method of claim 26, wherein moving the first spinousprocess and the second spinous process towards one another includesengaging a top surface of one of the first and second spinous processeswith a first portion of a pair of compression pliers, engaging a bottomsurface of the other of the first and second spinous processes with asecond portion of a compression pliers, and compressing the first andsecond portions of the compression pliers.
 28. The method of claim 13,wherein creating the hole includes passing a portion of a punching toolthrough at least one aperture of the lateral walls and through bonytissue of the spinous process.
 29. An implantableinterlaminar-interspinous stabilization system comprising: a U-shapedimplantable device comprising an inferior section, a superior section, amidsection extending therebetween, and a pair of lateral walls extendingfrom each of the inferior section and superior section for engaging aspinous process of a vertebra, each of the lateral walls including anaperture for receiving a bone fastener, each of the lateral wallsincluding an aperture for receiving a bone fastener, wherein eachaperture of the lateral walls includes a countersink; a bone fastenerfor securing the implantable device to the spinous process; an insertiontool for inserting the bone fastener through the apertures of theimplantable device during implantation of the system; and a pair ofcompression pliers for positioning a spinous process between each pairof lateral walls.
 30. A method of stabilizing a spine, comprising:selecting a vertebral level to be treated; positioning a U-shapedimplant between two adjacent spinous processes of the selected vertebrallevel, the implant comprising: an inferior section, a superior section,a midsection extending therebetween, and a first pair of lateral wallsextending from at least one of the inferior section and superiorsection, each of the lateral walls including an aperture for receiving abone fastener, wherein the pair of lateral walls are positioned onopposite sides of a spinous process of the selected vertebral level; andsecuring the implant to at least one of the adjacent spinous processesby using an alignment tool to pass a nut and bolt through the aperturesof the lateral walls, wherein the step of securing includes aligning thenut with the aperture of the lateral wall located on the opposite sideof the spinous process as the bolt such that the bolt passes through thespinous process and joins the nut at a threaded connection, and whereinthe alignment tool is configured to hold the nut and bolt and alignthreaded portions of the nut and bolt.
 31. The method of claim 30,further including tightening the threaded connection between the nut andbolt by turning a gear mechanism of the alignment tool to rotate the nutrelative to the bolt and thread the nut to the bolt.
 32. A method ofstabilizing a spine, comprising: selecting a vertebral level to betreated; positioning a U-shaped implant between two adjacent spinousprocesses of the selected vertebral level, the implant comprising: aninferior section, a superior section, a midsection extendingtherebetween, and a first pair of lateral walls extending from at leastone of the inferior section and superior section, each of the lateralwalls including an aperture for receiving a bone fastener, wherein thepair of lateral walls are positioned on opposite sides of a spinousprocess of the selected vertebral level; moving a first spinous processand a second spinous process towards one another before securing theimplant to the first spinous process and second spinous process byengaging a top surface of one of the first and second spinous processeswith a first portion of a pair of compression pliers, engaging a bottomsurface of the other of the first and second spinous processes with asecond portion of a compression pliers, and compressing the first andsecond portions of the compression pliers; and securing the implant to afirst spinous process by passing a first bolt through the aperture ofone of the lateral walls of the first pair of lateral walls, securingthe implant to a second spinous process by passing a second bolt throughthe aperture of one of the lateral walls of the second pair of lateralwalls, wherein securing the implant includes aligning a nut with theaperture of the lateral wall located on the opposite side of the spinousprocess as the bolt such that the bolt passes through the spinousprocess and joins the nut at a threaded connection.